Thanks, Gerard.
Okay, I can add some more information then.
All the original smog equipment is in place. I did replace the gulp
valve to stop the thing from going vrooooom, BANG as I accelerated and
made a shift.
I checked airflow at the oil filler cap on top of the valve cover and I
am pulling a vacumn there, not blowing out air.
I probably have what I need to do a leakdown test but don't know how to
do it. I have a compressor and this particular gauge set
(http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=39224).
- Kendel
ps - Kate, coyotes keep the cat population down here in the desert, so I
have no need of firearms.
gerard wrote:
> Hi Kendel,
>
> Lots of possibilities here.
>
> First, since you mention the dipstick guide is broken, I would make
> sure you don't have blow-by pumping oil oil that hole. I have seen one
> engine that was in otherwise good shape do that. You don't say of the
> original smog equipment is in place so there are some variables there
> as well, particularly the PCV valve. You need one in place that works.
> These engines develop a lot of internal pressure especially if the
> rings are bad, and the oil will find it's way out wherever it can,
> especially through the rear seal. The best way to determine if you
> have a valve or ring problem is a leak-down test. If you aren't
> familiar, that requires a special set of gauges and some compressed
> air. My experience with rebuilding these engines is that the rings
> seize up or break when they have sat for a long time. Also, the ring
> lands widen further complicating the problem. I would run the engine
> until warm and then park it and observe where the oil drips.
>
> Balancing and adjustimg the carbs is a lengthy description, but
> basically, you want to start 12 flats down (2 full turns) from full up
> position and turn them up equally until a slight manual raise of each
> piston does not cause the idle to go up or down. Make sure the jets
> return freely to their rest positions and that the choke cable is not
> holding them open. Other issues common on that old a pair of SUs, is
> that the throttle shafts wear causing air to leak. Incorrect float
> levels will also cause rich mixtures. There are several other factors
> in balancing and adjusting. If you plan to do much work on the car,
> get a Bentley Publsher's workshop or a Haynes manual.
>
> Obviously, incorrect valve adjustment is a problem too. Get a remote
> starter switch to bump the engine over... or... If you take out the
> plugs, you should be able to easily turn the engine by hand or by
> putting the car in gear and rocking the car back and forth. If you
> don't have a position guide handy, the two numbers should add up to
> nine, i.e. adjust 1 with 8 fully open, 3 with 6 fully open, etc.
>
> This should keep you busy for a while.
>
> Gerard
>
> At 11:09 PM -0700 5/25/03, Kendel McCarley wrote:
>
>> Hi, all.
>>
>> I'm a new subscriber to the list with an immediate problem. I've had a
>> couple of Midgets follow me home in the last few months and I'm trying
>> to get one ready for a trip (a father/daughter thing where I'm going to
>> deliver the car to my dad... er, her granddad). This little '72 is
>> absolutely gorgeous, but isn't running so well. It was probably running
>> better when it was donated to the museum from which I acquired it, but
>> sat for most of the last five years in a metal building with no
>> attention (along with a couple of P-40s, an Osprey, a Quickie, an IL-2,
>> and... well, okay, it was a metal aircraft hangar stuffed with neat
>> aircraft awaiting restoration or repair). While it was inside at least,
>> the Tucson heat and dryness wasn't nice to some rubber bits.
>>
>> Anyway, I'm burning a lot of oil in this thing. I mean a lot. Like a
>> quart every sixty miles or so. At least I think I'm burning it instead
>> of just pouring it out on the road because I'm fouling number four plug
>> and I'm smoking out the tailpipe, particularly on acceleration and
>> particularly after the engine has run for a while. There's also
>> droppings in my driveway from somewhere on the bottom part of the engine
>> (dipstick cup pulls out of the block... not sure that's the problem).
>>
>> I've replaced the SU jets because the hose on one of them had split at
>> the end on the float bowl and believe I'm now running rich (long time
>> DGV user, first time SU tinkerer). The engine is down on power some
>> since the rejetting.
>>
>> The engine is running a little smoother since I put a hotter plug in #4.
>> Runs a lot smoother with a clean, non-fouled plug. Before, it would
>> get to where it wouldn't even idle after I'd driven it ten miles or so.
>> Just rough idle now. Compression is pretty even, but lower than the
>> Datsuns I've been used to at around 110psi. This is on a cold engine.
>> I started but didn't finish a valve adjustment because I couldn't figure
>> out how to hand turn the engine to the right place. Found number five
>> with too much gap and think number eight might not have any.
>>
>> So, here's the possible culprits I think I can name: 1) bad intake
>> seals, 2) worn intake valve guides, and 3) stuck oil rings. Gosh, I
>> sure hope it's not the rings because I don't have time to deal with
>> that.
>>
>> What advice do any of ya'll have to help me track this down and fix
>> it... expeditiously? Also, what's the recommended method for rotating
>> the engine for valve adjustment?
>>
>> - Kendel
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